Siloxane compounds and silicones have found many uses in modern industry. For example, siloxane compounds are widely used in the production of cross-linked silicone polymers. These polymers typically are produced by either a hydrosilylation reaction or a condensation reaction. In the hydrosilylation reaction, siloxane compounds bearing vinyl groups undergo addition to link individual molecules of the compounds through the formation of new Si—C bonds. The hydrosilylation reaction typically is catalyzed by platinum, which contributes to the cost of these polymers because the platinum cannot be recovered from the cured elastomer. In the condensation reaction, the siloxane compounds react in a condensation reaction to form new Si—O—Si linkages between individual molecules. This condensation reaction produces volatile organic compounds (VOCs) as a by-product.
Cross-linked silicone polymers can be used as sealants or encapsulants for electronics. In particular, cross-linked silicone polymers can be used as encapsulants for light emitting diodes (LEDs). These cross-linked silicone polymers are desirable because they do not interfere with the operation of the electronic components. However, the cross-linked silicone polymers that exhibit sufficiently high temperature stability to be used as encapsulants for higher power LEDs do not have a high refractive index. This lower refractive index means that the light output from the LED will be reduced due to internal reflections in the semiconductor die of the LED.
A need remains for siloxane compounds that are suitable for use in making cross-linked silicone polymers without generating a large amount of volatile reaction products, such as the carbon-containing VOC's produced by condensation cure cross-linked silicone polymers. A need also remains for siloxane compounds and cross-linked silicone polymers that exhibit a high refractive index and are therefore better suited for use in those applications that demand an encapsulant material exhibiting a high refractive index (e.g., LED encapsulant applications). A need also remains for processes for generating these siloxane compounds and cross-linked silicone polymers. The subject matter described in the present application seeks to address these and other needs.